1. Field of the invention
The present invention relates to a method for formation of barium titanate film and, more particularly, a method for forming thin films of barium titanate on substrates.
2. Description of the prior art
Barium titanate, BaTiO.sub.3, has widely been used as a material for various electronic parts such as, for example, capacitors, resonators and the like. In order to apply barium titanate to such electronic parts, it is required to form thin films of barium titanate on substrates having various shapes and properties. To this end, there have been proposed various methods for fabrication of barium titanate thin films. For example, JP-A- 61-30678 discloses a method for formation of barium titanate thin films, employing chemical treatment of a surface of metallic titanium. JP-A- 02-94209 discloses a method for formation of barium titanate thin films, employing sputtering in which materials for barium titanate are sputtered from a cathode in electrical gas discharges. JP-A-H2-258700 discloses a method for formation of barium titanate thin films, utilizing plasma vapor deposition.
However, the above methods include various problems awaiting a solution. In the method disclosed in JP-A- 61-30678, the substrate is limited only to metallic titanium, thus making it impossible with this method to form thin films of barium titanate on substrates other than metallic titanium. In the method disclosed in JP-A- 02-94209, sputtering requires use of complex and expensive equipments, resulting in considerable increase of equipment investment. In the method disclosed in JP-A- 02-258700, discloses a plasma method utilizing plasma for deposition of thin films. This method requires complex and expensive equipments and can be applied only to substrates which can stand high temperatures, resulting in limitation of materials used for substrates.